In recent years, the use of special exercises and associated equipment has become relatively highly developed and has been scientifically applied as physical therapy for the restoration of injured limbs as well as for routine use by athletes and others in building muscles or increasing physical strength and stamina.
Numerous papers and articles have been written advocating special types of exercises for specific purposes. Thus, for example, isotonic (constant force) exercises will be recommended in one case while isokinetic (resistance directly proportional to the force exerted) exercises are preferred in another.
There is a need, therefor, for a versatile exercising system with a capability to provide a wide range of operating modes so that the need for a variety of special equipment is thereby obviated.